Food and drink products and other perishable items are often packaged in tubular containers which are sealed at both ends. These tubular containers typically include at least one structural body ply and are formed by wrapping a continuous strip of body ply material around a mandrel of a desired shape to create a tubular structure. The body ply strip may be spirally wound around the mandrel or passed through a series of forming elements so as to be wrapped in a convolute shape around the mandrel. At the downstream end of the mandrel, the tube is cut into discrete lengths and fitted with end caps to form the container.
Tubular containers of this type typically include a liner ply on the inner surface of the paperboard body ply. The liner ply prevents liquids from leaking out of the container and also prevents liquids from entering the container and possibly contaminating the food product contained therein. Preferably, the liner ply is also resistant to the passage of gasses, so as to prevent odors of the food product in the container from escaping and to prevent atmospheric air from entering the container and spoiling the food product. Thus, the liner ply provides barrier properties and the body ply provides structural properties.
Conventional techniques for constructing composite containers involve flooding one surface of the paperboard body ply with a liquid adhesive to facilitate bonding of the body ply to the interior liner ply to form the composite container. Since the liquid adhesives contain a large quantity of water, usually at least 50%, a large amount of moisture is added to the container. In most cases, the moisture reduces the compression strength of the container. This requires additional processing steps to dry the container prior to shipping. These processing steps add cost and delay. As a result, there is a need in the art for a method of eliminating the added cost and reduced container strength caused by the addition of moisture to the container. In addition, the adhesives are not inexpensive and it would be desirable to decrease the total amount of adhesives used to reduce the cost of materials for each container.